Electromagnetic rock drill and chipping hammer.



O. E. ADAMS.

ELECTROMAGNETIC ROCK DRILL AND CHIP-PING HAMMER.

APPLICATION FILED MAY 14, 1908. I Patented Mar. 5, 1912.

2 SHEETS-SHEET 1.

(lwo'anuga C. E. ADAMS. I

ELECTROMAGNETIC ROCK DRILL AND GHIPPING HAMMER.

APPLICATION FILED MAY14, 1908.

1,019,213, Patented Mar. 5,1912.

2 SHEETS-SHEET 2.

w AI 3:

UNITED STATES PATENT FFICE.

CLARENCE E. ADAMS, OF LEBANON, INDIANA.

ELECTROMAGNETIC ROCK DRILL A-ND CHIPPING HAMMER.

Specification of Letters Patent.

Patented Mar. 5, 1912.

Application filedMay 14, 1908. Serial No. 432,921.

- Hammer, of which the following is a specification.

This invention has reference to improvements in electro-magnetic rock drills and chipping hammers, and its object is to produce a means whereby an electric current is utilized for causing a rapid succession of blows to be given to the drill or hammer as the case may be.

The invention will be best understood from a consideration of the following detailed description, taken in connection with the accompanying drawings forming a part of this specification, in which drawings:

Figure 1 is a longitudinal section with parts in elevation of a tool support con structed in accordance with the present invention and designed to be carried by an operator and directed by him to the work. Fig. 2 is an end view looking from the tool carrying end of the structure. Fig. 3 is a diagram showing the electric circuit. Fig. 4 is a longitudinal section of the tool carrier constructed in accordance with the present invention, and showing the automatic feeding mechanism, and Fig. 5 a detailed view of the valve mechanism used in conjunction with the structure of Fig. 4, Fig. 5 being drawn on a larger scale than Fig. 4.

Referring to the drawings there is shown a rectangular frame 1, haying end members 2, and a central member 3. This frame is made of laminated iron and the lamina are secured together-in any suitable manner, as by non-magnetic rivets or bolts or by suitable cheek plates of non-magnetic metal. Secured to one end of the frame 1 is a head 4, and secured to the other end of the frame 1 is a block 5 on which is formed a handle 6 of suitable shape to be grasped by the hand of the operator. Slidable in the head 4 is a block 7 preferably cylindrical in shape but not necessarily so, and this block 7 extends for a distance into the space between the end 2 of the frame 1, and the central portion 3 of said frame. The outer or exposed end of the block 7 is formed with a suitable pocket 8 for the reception of a tool, of proper-form such as a drilling tool or a cutting tool, so that the device may be used for drilling. or chipping, or cutting. or riveting, or any other operation for which it is adapted. The block 7 may be held from dropping out of the head 4 in any suitable manner.

Secured in the spaces between the ends 2 of the frame 1 and the central portion 5v are spools 9 of suitable insulatingthereo materhl, and these spools are each so formed as to receive two coils. The outer portions of these spools receive coils 10 and 11, while the inner or contiguous portions of the spools receive coils 12 and 18, all of which coils will be referred to hereinafter.

The spools 9 are hollow and one of the spools receives the corresponding end of the block 7 where it projects inward beyond the corresponding end 2 of the frame 1.

The central member or vweb 3 of the frame 1 has a central passage 14, in linewith the block 7 and with the openings in the center of the spools, and housed in the spools and in the opening in the member 3 of the frame 1 is a cylindrical block 15, constituting the hammer or armature of the device as will hereinafter appear.

The end 2 of the frame 1 remote from the end carrying the block 4 has a central perforation 16 in line with the perforation 14 of the member 3. Housed in this perforation and in the corresponding end of the contiguous spool 9 is another cylindrical block or pole-piece 17. This pole-piece 17 has at one end an axial stem 18 passing through a block 19, housed in a perforation or passage 20 in the handle block 5, and the stem 18 has its outer end headed, so that the block 19 cannot escape from the stem 18. The block 19 is spaced on the stem 18 a shortdistance from the block 17, and surrounding the stem 18 between the contiguous faces of these two blocks is a helical spring 22. Y

The handle 6 and corresponding portion of the'block 5 is formed with a slot 23 for the reception of a hand lever 24 having its shorter end 25 appropriately formed to enter a recess 26 in one side of'the block 19. The hand lever 24 is constantly urged in one direction by a spring 27, housed in a recess 28 in ,the handle 6, and the tendency of the spring is to maintain the block 17 at the inward limit of its movement into the corresponding spool'9. I

The distance between the inner end of the block 7 and block 17 when the latter is at its outermost position is considerably greater than the length of the block 15, so that tln latter may move longitudinally for a dis tance before engaging either the block 7 o he block 17.

The structure forming the subject matter of the present invention is designed to operate by the conjoint action of both continuous and alternating electric currents, and consequently there are provided two circuits, one carrying continuous current, and the other carrying alternating current. The electric circuits are indicated diagrammatically in Fig. 3, where the continuous mains or leads are indicated at 27, and the alternating current mains or leads are indicated at 28. The coils 10 and 11 are coupled together in series but in reverse order, and are branched across the mains 28. The coils 12 and 13 areconneoted together in series without being reversed and are branched across the leads 27. Now let it be assumed that continuous current is flowing in the mains or leads 27, then the two coils 12 and 13 are charged and, attracting the core 15 equally, the latter remains quiescent. Suppose now that an alternating current is flowing in the mains or leads 28. Let it be supposed that the coils 12 and 13 develop north and south polarity respectively in the core 15. Let it also be supposed that at a certain instant of time the current flowin throughthe coil 10 also develops north p0 arity. .At the same instant the current flowing through the coil 11' will develop a north polarity in the core because of its reversed winding. Under these conditions the coils 10 and 12 coact to produce an augmented field of north polarity while the coils 11 and 13 react one on the other to neutralize or eliminate the magnetic eflect of these two coils 11 and 13.

The core or armature 15 is thereupon strongly attracted to the coils 10 and ,12. On the reversal of the current on the mains .28 the coils 11 and 13 become coactive to strongly reciprocated in synchronism with the period of the current flowing through the. mains 28. This action continues so .long as the circuit through the mains 28 is completed.

The self-induction of the alternating current flowing throu h the coils 10 and 11 produces a choking e ect upon the alternating circuit thus cutting down the efficiency of the device. To overcome this defect I provide other coils 30 in inductive relation to the coils 10 and 11 and these coils 30 are included in a circuit 31, closed on itself and including an adjustable resistance 32. The closed inductive circuit 31 will cut down the self-induction of the circuit through the coils 10 and 11 and thereby permit a greater flow of current through these coils than would otherwise take place, and this flow of current may be regulated at will by the ad justable resistance or rheostat 32 so that the rheost-at becomes a governing means for modifying the current operating the drill or cutter.

When the core or armature 15 is impelled toward the right as in Fig. 1 it imparts a hammer blow to the end of the block 7, and this hammer blow is in turn imparted to the tool carried in the socket 8. When the armature 15 is moved toward the left as viewed in Fig. 1 it ultimately comes in contact with the block 17, which block is backed up by the spring 22. The blow imparted by the armature 15 is therefore, yieldingly resisted by the pole-piece 17, until the armature is finally brought to rest. The result is that the shock of the blow of the armature 15 against the pole-piece 17 is gradually absorbed by the spring 22 so that the block 17 acts as a cushion or buffer for the armature 15 and the force of the blow of the latter is gradually absorbed without shock. The result of this is thatwhile the forward blow of the armature 15 is active upon the block 7 to drive the drill or cutting tool into the work, the return blow'is largely inactive being absorbed bythe spring 22, while the reaction'of this spring serves to impel the rent flowing through the coils 10 and 11 by means of the resistance or rheostat 32, the extent of travel and consequently the force of the blow impartedv by the hammer or armature 15 may be regulated by a suitable manipulation of the lever 24. When this lever 24 is moved by the hand of the operator against the action of the spring 27, then the block 19 is drawn toward the handle end of the device, and the block 17 participates in this movement. The result is that vthe distance between the inner end of the block 7 and the inner end of the pole-piece 17 islengthened and the effective travel of the armature 15 is correspondingly increased. Thus the operator, by a suitable manipulation of the lever 24 may regulate the hammer blow of the armature 15 independent of the current flowing through the coils '10 and 11.

The structure so far described is particularly adapted for chipping, or cutting, or riveting, or similar operations. In Fig. 4 the same structure is shown as modified for heavy drillin where the operationwould be too heavy or a hand held tool. 139

In the structure shown in Fig. 4 the handle block 5 is replaced by a head 33 and this head is entered by a central threaded recess 34, into which recess is screwed a peripherally screw threaded ring 35 having a central plainorifice, through which extends the corresponding end of the block 17. Beyond the ring 35 the block 17 has a cylindrical extension 36, and at the junction of this extension with the block 17 there is formed an annular flange 37, which when abutting against the ring 35 serves to pre vent further movement of the block 17 into the coil 10. Screwed into the recess 34 is a threaded end of a neck 38 formed on one end of a cylinder 39, and that end'of the neck 38 entering the recess 34 is counterbored as shown at 40 to receive one end of a helical spring 41 surrounding the extension 36 between the neck 38 and the flange 37. Between the bore of the neck 38 and the interior of the cylinder 39 is a web or diaphragm 42 and the bore of the neck 38 is of such size as to snugly receive the extension 36 of the block 17 fora purpose which will presently appear. The Web 42 is pierced by two passages 43 and 44, each enlarged to receive a ball valve 45 and each provided with an appropriate valve seat 46 for the ball valve. Other types of Valves may of course be employed.

Screwed into a suitably threaded portion of the passage 43 is one end of a pipe 47 extending to within a short distance of the other end of the cylinder 39 and terminating close to the head 48 of said cylinder. Screwed into a suitably threaded portion of the passage 44, is another pipe 49 extending to and through the head 48 and terminating at the exterior surface thereof, and there opening. The end of the passage 43 remote from the valve seat 46 in said passage may be partially closed as indicated to retain the ball valve 45, by upsetting the metal at the said end of the passage as is customary, ,while the pipe 49 will retain the ball valve in the passage 44.

Surrounding the cylinder 39 and extend ing beyond the free end thereof is another cylinder 50 having at its outer end a pointed cap 51, which also serves as a closure for the corresponding end of the cylinder 50. The inner end of the cylinder 50 is formed with a circumferential flange 52 counterbored for the reception of packing and entered by a suitable gland 53 held in place' by screws 54 or other suitable means. The cylinder 50 is free to move longitudinally on the cylinder 39, but the escape of fluid under pressure between the said cylinders is prevented by the packing held in place by'the gasket 53.

Leading from the passage 44 through thediaphragm 42, and opening into the interior of thecylinder 39 is a by-path condrilled.

duit 55 which may be throttled or entirely closed by a suitable needle valve 56, carried by the neck 38. g

Let it be assumed that within the cylinder 39 is some fluid such for instance, as oil, and let it further be assumed that the point 51 is in engagement with some solid obstruction, while a drill carried by the block 7 is in engagement with the part to be If now it be further assumed that the armature 15 is being reciprocated by the action of the electric current so as to deliver blows to the drill, each return movement of the armature 15 will be resisted by the block 17, and the spring 41, but the block 17 will yield for a distance against the action of the spring 41 and the action of other yielding means in its path. When the block 17 moves toward the right as viewed in Fig. 4 it will draw a certain amountof fluid from the cylinder 39, through the pipe 47 into the interior of the neck 38, and when the block 17 is moved toward the left as viewed in Fig. 4 by the impact of the armature 15 then the valve 45 in the passage 43 is closed against its seat 46, and any fluid which may be in the interior of the neck 38 is forced through the valve passage 44 and pipe 49, into the interior of the cylinder 50. The extension 36 of the block 17 thus operates as a pump piston drawing fluid from the cylinder 39 and forcing it into the cylinder 50 by the movement imparted to the block 17 by the armature 15. As fluid is pumped from the cylinder 39 into the cylinder 50, pressure is generated in the last named cylinder, and the point 51 is slowly forced away from the head 48 of the cylinder 39, thus causing the block 7 at the other end of the frame 1 to be forced toward the work, thus automatically feeding the drill to-the work as the work progresses.

If it be found that the feeding operation is too rapid, or if under some circumstances it be desired to stop the feeding operation, then the needle valve 56 is opened to a commensurate extent, so'that. the fluid is pumped back into the cylinder 39 eitherpartially or entirely as may be desired.

If air only be pumped from the cylinder 39 into the cylinder 50 or if a considerable body of air be confined within the cylinder 50 before any liquid be pumped therein. then the feeding pressure or impulse will he correspondingly elastic depending upon the amount of air confined within the cylinder 50 before the liquid is pumped therein.

The frame 1 is made as highly laminated as may be necessary to prevent hysteresis or the formation of eddy currents.

Referring once more to the structure of Fig. 1 it will be seen that there is formed through the handle 6 and handle block a passage or conduit 57. This is provided for the purpose of carrying the conductors to the coils 10, 11, 12 and 13. Of course any other means of connecting or carrying the conductors to the coils may be provided.

While I have described in some detail the structures shown in the drawings, it is to be understood that the invention is not to be 'confined to the exact construction there The current mains 27 and 28 may come from separate and distinct sources of current of proper character or a single lt g. I I,

mer, means for producing constant magcurrent dynamo may be used to furnish the current, and thecontinuous current may be obtained therefrom, through the intermediary of a suitable commutator.

It is to be observed that the coils'lO, 11, 12 and 13 are in .efi ect solenoids while the frame-work 1 constitutes an iron-clad support therefor, and this iron-clad support or casing may extend to any desired'extent about the coils. and the block 17' constitute the polar extremities of the coils between which the armature 15 reciprocates, and this armature consists of a plain piece of iron 01'' cylindrical or other form, and is entirely bare of any extraneous structures whatsoever. Consequently the-moving parts of the structure are of the simplest possible nature. and entirely free from. all complexities whatsoever.

Therefore the structure may work for long periods of time without the necessity of repairs or the liability of breakage, or deterioration. Y

, What is claimed is :v v

1. In an electric drill or chipping hammer, means for producing constan magnetic fields, means for alternately aug ,ent' the strength of one" field and simultaneous y neutralizing or reducing the strength of vthe other field, means for counter-acting the counter-electric motive force developed by the alternate varying of the strength of the magnetic fields, a freely. reciprocating armature in said, fields constituting-a hammer, and a tool holder in the path of the hammer in one direction of its travel. I

2. In an electric drill or chipping hammer,- means for producing constant magnetic fields, means for producing alternating magnetic fields in operative relation to the constant magneticfields to alternately augment the strength of each field I and simultaneously reduce or neutralize the other field, and means for counter-acting the self-induction of the alternate fields.

3. In an electric drillor chipping hammer, means for producing constant magnetic fields, means for producing alternating magnetic fields inoperative relation to the con- ,nating fields.

Furthermore the block 7' stant magnetic fields to alternately augment the strength of each field, and simultaneously reduce or neutralize the other field,

tion to the ,means [for producing the ialter- 5,. In an electric drill or chipping hamnetic fields,'means for producing alternating magnetic fields in operative'relation to the constant magnetic fieldsto alternately augment the strength of each field and simultaneously 'reduce or neutralize the other field, and a closed circuit in-inductive relation to the means forproducing the alternating fields, said closed circuit including an adjustable resistance.

i 6. In an electric drill or chipping hammer, solenoids in series and arranged to be energized by a continuous current, other solenoids 1n serles and in reversed relatlon,

said second named solenoids being in fixed operative relation to the first named solenoids and arranged to receive alternating currents, a closed circuit in inductive relation to the alternating current solenoids, an

armature in reciprocating relation to the solenoids, and a tool holder in the path of the armature.

7. .In an electric drill or chipping ham-- mer, solenoids in series and arranged to be including an adjustable resistance, an armature in reciprocating relation to the solenoids, and a tool holder in the path of the armature.

8. In an electric drill or chipping hammer, solenoids in alinement and arranged to be' energized by a continuous current to produce magnetic fields .of respectively opposite polarity, other solenoids in inductive relation to the first named solenoids and adapted to receive alternating currentto alternately neutralize and augment the magnetic fields produced by the first named solenoids, a closed circuit in inductive relation to' the alternating current solenoids, an armature in reciprocating relation to the solenoids, and a tool holder in the path of the armature.

posite polarity, other solenoids in inductive relation to the first named solenoids and adapted to receive alternating current to alternately neutralize and augment the magnetic fields produced by the first named sole- 10 noids, and a closed circuit in inductive relation to the alternating current solenoids, and including an adjustable resistance.

In testimony that I claim the foregoing as my own, I have hereto aifixed my signature in the presence of twowitnesses.

L. M. BEOVEN, VIOLET HESTER. 

